Cellulosic product



Aug. 25, 1959 K. J. HARWOOD CELLULOSIC PRODUCT Filed Sept. 30. 1954 Afl.

United States Patent Olice 42,900,980 Patented Aug. 25, 1959 2,900,980CELLULosIC PRODUCT Kenneth J. Harwood, Neenah, Wis., assignor, by mesneassignments, to Kimberly-Clark Corporation, a corporation of DelawareApplication September 30, 1954, Serial No. 459,473

18 Claims. (Cl. 12S-290) This invention relates to an improvedcellulosic product, iand more specifically, an improved sanitary orcatamenial napkin which embodies an absorbent pad element and a Wrapperaround such pad element, and to an improved form of material adapted foruse in such Wrapper and for other purposes. Although other Wrappingsmaterials are being used around pads, the most common wrapper materialhas been woven` surgical gauze which provides Ia highly pervious Wrapperwhich permits the menstrual exudate `to readily pass through thewrapperand 'be absorbed by the absorbent pad. Gauze has been very satisfactoryfor the indicated purpose because of its substantial tensile strengthwhich enables such material to effectively hold and confine theabsorbent pad and to provide attachment tabs which extend beyond theends of the absorbent pad for supporting the napkin from a belt orgarment through the agency of buckles or pins.

i Gauze wrappers for sanitary napkins have, however,

lheen somewhat objectionable in several respects. For example, gauzethreads are fairly hard and tend to be quite abrasive against the skinof the wearer of the napkin so `that chang and irritation are likely tooccur. This abrasive effect has been avoided in certain products by theapplication of la facing of free, unspun and unfelted yor only looselyfelted fibers, `such 4facing being very light in weight and justsuilicient to produce more or less `of a shielding effect over the gauzethreads, the Weight of the fiber applique being also kept very low inorder to avoid as far as possible, reduction of the permeability of thegauze material. An example of that construction is shown in U.S. PatentPatent No. 2,564,689.

The Weaving of gauze is a relatively slow operation,

many gauze weaving looms being operated tat the rate of about one andone-half feet per minute when weaving gauze having a thread count of 18x 14 (18 lengthwise threads per inch of Width and 14 crosswise threadsper inch of length) and a fairly strong and tightly spun thread is usedto avoid thread breakage in the Weaving operation. Hence, the threadsfound in woven gauze are ordinarily hard and abrasive as aforesaid.Also, for sanitary napkin wrapper purposes, a very open mesh gauze ismost suitable in order to provide the greatest permeability. However,although gauze more open than 18 x 14 may be woven, the more open weavesare seldom satisfactory because they tend readily to fray or becomedistorted, that is to say, the threads tend readily to shift from theirnormal positions, providing uneven and unsightly thread disposition inthe relatively unstable, more open weaves. In ,18 x14 gauze webs whichhave heretofore been generally used' for sanitary napkin Wrapperpurposes, the weight of the gauze averages about 16 to 16.5 grams, thisbeing an important factor in the total weight of the sanitary napywhichdesirably is made as light in Weight as possible without impairing itsfunctions.

Another diiculty in respect of the use of gauze of more open mesh forsanitary napkin wrapper purposes is incident to the necessity ofemploying Well bleached gauze in order to obtain the desired clean,white and sanitary appearance. As a practical matter gauze is woven fromunbleached cotton threads `and the woven fabric subjected to bleachingoperations. Conventional bleaching operations involve `substantialhandling of the fabric which may Ibe accompanied by severe and extensivefraying even in such meshes as 18 x 14 and the fraying becomes moresevere as the mesh is made more open. For sanitary napkin wrapperpurposes, it is important that the wrapper Ifabric be of uniform threaddistribution, that is to say, free from distorted thread lay or fraying,in order that the product present a very neat appearance, and for otherreasons.

ln some prior Lattempts to avoid the employment of woven gauze forsanitary napkin purposes, various porous paper and non-Woven fabricsheetings have been substituted for gauze, but even in such substitutedconstructions it has usually been found necessary to incorporate atleast a narrow strip of gauze extending from end to end of the napkin,i.e., from the free end of one attachment tab to the free end of theother attachment tab, so as to provide the necessary `strength forsupporting the napkin in the usual manner. Also, paper Iand non-Wovenfab-ric Wrappers must be made sufficiently strong to effectively retainand to support the absorbent pad and this requirement necessitates theuse of such heavy or dense paper or nonwoven fabric that perviousnesshas been quite objectionably impaired.

According to the present invention, la wrapper is provided whichconsists yof textile or other threads extending lengthwise and crosswiseas in la Woven gauze sheet but in which the threads are not interwovenor interlaced but are otherwise securely held in fixed relationship toeach other so that the fabric is highly stabilized and may be of almost`any desired very open mesh, for example, 4 x 4. Known apparatus, not apart of the present invention, is capable of operation at many times theproduction speed of gauze weaving looms, to produce such fabric. Fabricmade of such cross-laid threads, is referred to hereinafter =by theWords crosslaid fabric.

The main objects of the present invention are to provide a sanitarynapkin embodying an absorbent pad element and a Wrapper around such padelement wherein the wrapper embodies a stable thread web of very openmesh so as to be highly permeable; to provide a sanitary napkin of thecharacter indicated in which the wrapper is soft and flexible so that'it is readily conform- -able to the enclosed pad body; to provide anapkin o-f the character indicated in which the covering wrapperembodies strength and security giving threads but nevertheless exhibitscomfort giving characteristics of nonirritating or non-chang surfacesoftness and smoothness; to provide an improved fabric embodyingStrength giving threads, which fabric is suitable for many purposesincluding use as a sanitary napkin Wrapper having the aforesaiddesirable characteristics; and in general, it =is the object of thisinvention to provide an improved absorbent bandage such as a catamenialnapkin and an improved fabric which is suitable for the vn'apper com,-ponent of such a napkin and for other purposes.

Other objects and advantages of the invention will be understood byreference to the following specification and accompanying drawingwherein there is illustrated a selected form of the 'improved sanitarynapkin.

In the drawing:

Figure l is a perspective illustration of a sanitary napkin;

Figure 2 is an elevation of a piece of fabric made aecording to thisinvention and used in the wrapper of the sanitary napkin;

Figure 3 is a perspective representing an element entering into theconstruction of the fabric material shown in Figure 2;

Figure 4 is a cross-sectional view on the line 4-4 of Figure 2;

Figure '5 is asection on .the line 5 5 of F1g11re 2; and

Figures 6 and'7 `are schematic representations of method steps andmechanisms for producing 'certain components of the improved sanitarynapkin. v

A sanitary napkin, represented in Figure 1, comprises an absorbentpadbody 1 which may be of any suitable construction, the details of whichare not important or critical so far as the present invention isconcerned. This absorbent pad body, in one embodiment, was formed of acombination of crepe tissue paper plies and an intermediate layer ofAso-called duff material, end portions of the crepe paper pliesV'ex-tending beyond the intervening utf layer and being embossed undersubstantial pressure and thereby united so as to aid in holding theVintermediate fluff layer in place. The pad body 1 is enclosed in awrapper 2 which is initially inthe formy of an elongated rectangularsheet or web of material, such web being wrapped around the pad body 1transversely of its length so that opposite side margins of the wrappingsheet overlap one another as indicated at 3 in overlying relation on oneface of the pad body l. The wrapper 2 is thus formed into more or lessof Ia tube about the absorbent pad 1, end portions 4 and 5 of thewrapper projecting beyond the opposite ends of the pad 1 to constitutethe usual attachment tabs for engagement with the buckles of asupporting sanitary belt or other supporting means. In some instancesthe tabs maybe'shortened and provided with attachment loops in a knownmanner.

The wrapper 2 of the napkin is formed of a cross-laid thread backing orcarrier web 6 comprising a series of spaced, substantially parallellengthwise extending threads 7 and a series of spaced, substantiallyparallel crosswise extending threads 8, and an applique 9 of fibers. Thethreads S, in this instance, are disposed substantially perpendicularlyto the threads 7 so as to resemble woven gauze, and said threads S areadhesively bonded to said threads 7 by adhesive 1d on the threads '7,said adhesive serving to also bond said fiber applique to thethreadformed web. If desired, the cross-laid threads 7 and 8 may bedisposed diagonally of the length of the web so as to present a diamondnetwork pattern, and there may be one or more additional sets of threadscross-laid on those illustrated, the threads of such additional setsbeing disposed at angles to the threads of both of said other sets.Parallel thread `arrangement is not essential and may give way tonon-parallel threads including various arrangements such as sets of wavyor undulating threads which threads may extend in one general directionwithout necessarily being parallel to one another.

The adhesive i6 on the threads 7 is preferably applied so as to bediscontinuous along the lengths of sa-id threads, irregularly spacedbreaks or interruptions in said adhesive being indicated at lll. Thecross threads 8 will seldom engage adhesive-free areas on adjacentlengthwise threads so that said cross threads will, not withstandingsaid adhesive-free lengths, become effectively bonded to theadhesive-bearing threads. The cross threads are caused to engageadhesive bearing areas of the lengthwise threads with sucient intimacyto insure adhesive interbonding of said lengthwise and crosswisethreads, and calendering of the web may be employed to increase oramplify such intimacy. Due to this adhesive interbonding of thelengthwise andcrosswise threads it is very practicable to'produce stablecross-laid thread webs having such open mesh construction as: 4 x 4. Theexample represented in Figure 2 of the drawing is l0: x 5 construction,Figure 2 being greatly enlarged. v The fiber applique'9 may consist ofnatural or synthetic fibers or mixtures thereof and said fibers may bedeposited ina more or less haphazard arrangement as represented inFigure 2 so that some, if not most, of the fibers will engage at leastone `adhesively coated thread portion so as to be thereby directlyadhesively attached to the thread web. The fibers which form theapplique 9 also have a normal tendency to cling to engaged threadportions even in the absence of adhesive so that an important degree ofcohesion exists between the fibers and the engaged portions of theadhesive-free cross threads 8. Furthermore, intertwining of the'tbers inthe applique also serves to anchor bers to iibers so that a fiber whichhappens to miss engagement with any thread of the thread web maynevertheless be anchored thereto through the agency of other bers whichare directly attached to the thread web. Carded and similar fiber websmay also be employed to form the fiber applique. The fiber applique maybe preformed and applied to the backing web or the applique may beformed on the backing web by depositing thereon libers dischargedinunmatted or free condition from air-laying, carding, and other forms offree fiber delivering apparatus.

The ber applique may be of any desired weight suitable for any given useto which the fabric is to be put. For sanitary napkin wrapper purposesthe fiber applique '9 may be very light, for example, of the order of11/2 to 6 grams per square yard.

The fiber applique 9, even when made of very low basis weight, forexample, within the range of 11/2 to 6 grams per square yard, provides asignicant shielding elfect whereby the threads of the carrier web areheld out of intimate contact with the body of the wearer of thenapkin sothat chai-lng and irritating tendencies incident to the normal hardnessand abrasiveness of the cross-laid threads is largely avoided.Calendering will aid in this matter of avoiding chang tendencies, bymore or less attening the crossing areas of thelengthwise and `crosswisethreads so that the wrapper material exhibits an important freedom frompronounced thread crossing projections or knuckles such as occur VinWoven gauze.

By applying `the adhesive only to the threads extending in one directionas above explained, the normal softness and iiexibility of the otherthreads is preserved as a characteristic of the fabric. Also, byapplying theadhesive in short lengths so as to provide the adhesivefreeareas 1l at short intervals, the normal flexibility and softness of theadhesive-bearing threads is also `preserved to a significant degree.Furthermore, it is Vpreferred that the `adhesive `be of a permanentlyflexible character so as to thereby further avoid adhesive hardening orstiiening of the fabric.

Vsoak into the same is desirable to facilitate embedment -of some of thebers of the applique `9 into said adhesive,

and also embedment of one set of threads in the adhesive carried by theother. Also, surfaced adhesives usually have a lesser hardening eifectonfthe threads.

lOne form of mechanism for producing the illustrated cross-laid fabric,is schematically represented in Figure 6 where the longitudinal threads7 are represented asbeing guided over an adhesive coating roll 12 andthence into the lform of a cylinder around aimandrel-l. Suitable meansindicated at 13a may be employed to-guide the threads into the desiredspaced relation around said mandrel. The cross threads 8 are Wrapped.around the thread cylinder `on the mandrel-by -a rotating device 14 andbecomes adhesively bonded to said threads .7 by the adhesive on thelatter. The cylinder of cross-laid threads is slit as indicated at.15and laid open and then passed between the rolls .of acalender roll stackas rep*- resented at 16. Depending upon the type of adhesive used,provision rmay be made to -dry or partially dry jthe adhesive on thethreads to prevent-wet adhesive from 'hesive on the longitudinalthreads.

gumming up the guide means 13a and mandrel 13, and suitable means may beprovided, for example heating or moistening means, for reactivating theadhesive at the required time to make such yadhesive useful for bondingthe threads together and other components to the threads. Othermechanisms for producing the cross-laid thread fabric may be employed,the schematically represented mechanism just described being merelyrepresentative.`

To produce the adhesive free areas shown atf11 (Figure 2) on the threads7, the adhesive applyingi roll 12 may be formed with recesses (notshown) which will not apply adhesive in the areas 11`or said roll `maybe of plain cylindrical form and rotated so as to have a surface speedwhich is slower than the speed of travel of the thread web, whereby thefaster movement of the threads would tend to stretch the adhesive as itleaves the roll; such stretching of the adhesive will cause frequent butirregularly spaced breaks in the adhesive on the threads so that theadhesive will, in effect, be discontinuous along the lengths of thethreads 7.

In some instances, instead of applying the adhesive by means of anapplicator roll the threads may be coated continuously with adhesive bybeing passed through a bath of the desired adhesive. The adhesive may beprepared so that the threads passed through such a bath will pick upadhesive coatings of the desired thickness and surfacing tendencies.Also, suitable doctoring means may be employed in association witheither or both the threads and an applicator roll to control thethickness of the adhesive coating on the threads.

The cross threads 8 and the fiber applique 9 are preferably deposited onthe adhesive bearing threads 7 while at least the surface of theadhesive remains sufciently active to adhesively bond the cross threadsand the fibers to the adhesive bearing threads substantially uponcontact of the cross threads and fibers with such adhesive. Thecross-1aid web may be guided from the cross-laying mechanism throughfiber depositing mechanism as represented at 18 in Figure 7, thecalender stack 16 being by-passed and its function performed by acalender 19 after `application of the fiber applique so that the fibersin addition to the cross threads are pressed into the ad- Said calender19 preferably embodies steel and cotton or other relatively hard andsoft calender rolls 21 and 22 respectively which will serve theaforesaid purpose without causing cutting or breaking of the threads atthe points of greatest pressure, i.e., at the thread crossings.

A hot calendering operation may be employed, especial-ly when theadhesive is of thermoplastic character, the heat then serving toreactivate the adhesive so as to facilitate embedment of threads andfibers in such adhesive. As indicated in Figure 7, it is preferred thatthe cross-laid web be passed through the liber depositing apparatus sothat the fibers will be deposited on the side of the web formed by theset of adhesive free threads, so that the longitudinal threads willserve as strippers to remove the cross threads and fiber applique fromthe cotton calender roll; also, the fiber applique and cross threadswill then prevent adhesive attachment of the longitudinal threads to thecalender roll 2l, and some of the fibers of said applique will aid inanchoring the set (or sets) of adhesive-free threads to the adhesivebearing threads as an incident to Ithe adhesive attachment of suchfibers to said adhesive bearing threads.

Instead of applying adhesive to the threads, said lengthwise threads, orthe cross threads, or both, may be formed of a mixture of cotton orother non-thermoplastic fibers or filaments, and thermoplastic filamentsor fibers, the threads being subjected to heat or other treatment tocause the thermoplastic component thereof to be sufficiently activatedto effect adhesive inter-attachment of the mutually crossing threads. Itis preferable when procuring bonding in this manner, that the set ofthreads on which other threads and fibers are deposited, containthermoplastic fibers and be subjectedto a thermoplastic fiber softeningoperation (heating, for example) before the other threads and fibers aredeposited thereon. VIn this manner the deposited threads and bers willbe` at leastl slightly adhesivelyattachedto the thermoplastic bearingthreads immediately upon `contact therewith. Again, the `adhesivebonding thus effected between the lengthwise and crosswise threads ofthe carrier web 6 and between the fibers of the applique 9` and thecarrier web, may be improved by again or further reaotivating thethermoplastic `fibers by a hot calendering operation whereby more`complete embedment of the interbonded threads and fibers may beeffected. The fiber applique 9 may also embody a percentage ofthermoplastic fibers (say from 5 to 15 percent or more), which will bereactivated and adhesively bonded to the threads of the carrier web asan incident to said hot calendering operation. In some instances, thebinder bers in the applique may alone be relied upon to hold the threadsof the carrier inrsubstantially fixed relationship to each other.

At least `one of the sets of threads 7 and 8, comprises threads of soft,low twist construction and both sets may advantageously be entirely ofsuch construction. Said threads may contain, for example, from 2 to 150individual continuous filaments per thread, the filaments being fairlyfine filaments, i.e., of the order of l to 15 denier rayon,` the threadsbeing of 30 to 150 denier and having a twistless than 6` per inch, butat least .a slight twist is desirable to hold the filaments together asan integrated thread. Filaments of material other than rayon may be usedbut rayon has been found to be very suitable.

In one practical embodiment, the cross direction threads 8 were made of40 rayon filaments to forma low twist thread of denier, the twist beingof the order of 4 turns per inch. The machine direction threads 7 weremade of 30 rayon filaments to form a low twist thread of 75 denier, thetwist being of the order of 21/2 turns per inch. These low twist finefilament threads 7 and 8, although initially of more or less roundcross-section, tend to assume a flattened oval shape in cross section asindicated at 20 in Figure 3, incident to winding of the same on spoolsand as an incident to the passage of the-threads over guide rods orrollers.` When such threads are fabricated into the described cross-laidthread fabric 6, this iiattened `cross-sectional form is advantageous inthat the Width of the threads falls into the plane of the fabric; hence,the crossings of the threads are initially quite flat and this atness isincreased, or to put it in another way, the thickness of the initiallyflat crossings is reduced, when the web is calendered as abovementioned.

The flattening of the threads as above explained provides a furtheradvantage in that flexibility of the fabric is improved due to theincreased fiexibility of the threads.

The multiple filament, low denier, low twist construction of the threadsemployed in the thread carrier web results in a thread fabric which isvery thin, soft and smooth notwithstanding the tendency of adhesive toimpart stiffness to the fabric.

Th inherent softness of said low twist threads permits the filaments inthe crossing thread portions to fan out to widened and iiattenedproportions as a result of thepressure of interengagement which isincident to the tension under which the threads are assembled in theweb. This flattening and widening provides enlarged areas of engagementand adhesive interattachment of the mutually crossing thread portions,said flattening and widening is, of course, increased by the subsequentcalendering operation which attens not only the crossing portions butthe entire lengths of the threads so that in the finished nonwovencarrier web 6, a highly desirable flatness and smoothness is attained.If the adhesive on the threads is of heat sensitive character, hotcalendering will aid in the flattening effect. i i t Because of the.soft `low twist construction of the threads, relatively ,lowcalendering pressure (for example about 85 pounds-perlineal inclrofcontact area when the rolls-are about `8inches in diameter) issufficient to producea very-satisfactory flattening effect. Thisrelatively low calendering pressure avoids the tendency of the threadsto cutone another when rthey arepressed together .under highl pressuressuch as are required when the `threads, are of harder, high twistVconstruction as in Woven gauze. Thecalendering operationreduces thecombined thickness of -the two interengaging, crossing threadportionsalmost to the thickness of the single thread portionsintermediate said crossings as shown in Fig. 5, the thicknessesVreferred to being normal to the plane of the web.

Because of the softness of the described low-twist, multiple filamentthreads, the cross thread portions intermediate the longitudinalthreads, tendto` settle into the plane of said longitudinal threads upondeposition of the cross threads onrthe longitudinal threads as shown(more or less schematically) in Fig. 4. Thisinitial nearlycoplanarrelationship is made more nearly complete as an incident tothercalendering of the carrier web 6 with the fiber applique 9 thereon,the interengaging crossing thread portions being pressed into each otheras above explained. Thelongitudinal threads are initially disposed incoplanar relationship, and this relationship is not disturbed'inthefabricating operations, so that the layer of longitudinal threadspresents a substantially smoother surface than is found on comparablewoven fabric.

The applique 9 of fibers, where said fibers cross over thread portions,are pressed into compacted, intimate engagement with said threadportions, while in the areas `of the openings or interstices of thebacking web, which Aopening areas comprise a great majority of the areaof the web, the fiber applique 9 exhibits a characteristic softness orflufliness. The very open mesh character of the web 6 probablycontributes to the tendency of the fiber applique to assume the saidsoft fiuffy condition in the spaces between threads. Hence, the fiberapplique 9, even though securely bonded tothe threads of the carrier webwill nevertheless provide a soft cushion-like facing on the carrier web.

'In onepractical'embodiment of the described crosslaid thread fabric of18 X 14 construction with cross threads of aboutlOO denier former of 40rayon filaments of about 2.5 denier, and machine Vdirection threads ofabout 75 denier formed of 30 rayon filaments of about v.2.5 denier, `theweight kof the cross-laid thread fabric,

including `the adhesive but no fiber applique, averages between 13 and-l4 grams per square yard, theadhesive accounting for about 4 grams ofsaid weight. A Woven gauze fabric of 18 x 14 construction embodying theusual s Warp and Y40s filling, weighs an average of'about 16.3 grams persquare yard. This comparison indicates the substantial reduction inweight which is attained in cident ito the employment of the describedcross-laid thread fabric instead of woven gauze. This weight reductionis practicably attainable incident` to the feasibility of producing thecross-laid, `non-woven thread fabric of threads of the aforesaid softcharacter and light weight. Weaving with such light weight threadstoproduce cornparable woven gauze, especially at high production speedsdesired, is very difficult'due to various factors such as the smooth,slippery surface characteristic of such threads; woven gauze producedfrom such threads frays very easily so that itsusefulness for sanitarynapkin wrapper and other purposes is ygreatly impaired.

In another practical embodiment of the described sanitary napkin, thewrapper 6 comprises a l0 x 5 thread `web-formedfof about75 denierlengthwise threads and aboutlO() denier crosswise threads, thelengthwise threads being.'v formed of 30 laments of about 2.5 denier andthe crosswise threads of 4() filaments of about 2.5 denier.

.-Thew'ebf4 so formed 4fweighs about 7 grams per square similar Wovengauze wrapper of the usualrBOs warp and .40S filling .weighs about 9grams per Square 'yard-but despite itsextra weight and strength, wouldnot, be very satisfactory as .a ,Sanitary napkin wrappertiennent''because ofits excessive ,fr aying or distorting tendency. Onthe last mentioned crossalaid thread carrier web, there was air-laid, anon-woven facing of comber cotton fibers having a weight 4of about 31/2grams Vper square'yard. This resulted in a very satisfactory, highlyliquid-permeable Wrapper for the absorbent ,pad of the sanitary napkin.The grade of cotton referred to as lcomber cotton comprises fibersranging in length from about #A6 of an .inch or even less to l inch `ormore withV a large proportion of the fibers being of an intermediatelength around TA6 ofan inch.

The thread forming filaments were of rayon having very smooth and shinysurfaces which imparted to the wrapper, a very desirable appearance.However, rayon filaments having a dulled, non-shiny surface-finish areavailable and may be employed if preferred.

-lnprodticingthe above mentioned l0 x 5 cross-laid thread web,`plasticized polyvinyl acetate adhesive in a solvent was applied togtheVmachine direction threads by an immersion process. Thecross threadswere deposited on the `adhesive bearing longitudinal threads while theadhesive on the latter remained active at least `on the surface of theadhesive so that the cross-'laid threads were immediately adhesivelyheldinpllace on the lengthwise threads. The thread web thusproduced wasthen passed through a machine. whereby. fiber was air-laid on the crossthread side ofthe web. Thereafter, the fiber applique bearing web Vwascalendered to'flatten'the threads and theircrossings, to improvertheembedment of the cross threads in the adhesiveron the longitudinalthreads, and to also effect embedment of some of the'fibers of saidapplique into said adhesive, thereby to securely'bond the vvarious partsofthewrapper to each other.

The calendering equipment included the heated steel Vrol-l representedat 2l in Figure U7, and a cotton calender roll 22, the web being passedthrough the calender with theflongitudinalthreads of the web next togthecotton -roll which-is normally the cooler of the-two rolls. I n `thisarrangement the fibers of the fiber applique werealso vpressed into thespace between the longitudinal threads as above explainedand asrepresented in Figure 4. -The steel roll was heated to` a temperature ofabout 300F. The calendering was effected under apressure of about poundsper lineal inch of calender roll (about eight inches in diameter) andthis pressure was sufficient to somewhat. increase the flatness of .thethreads, especially at their crossing portions so thatthe cross-laidthreadfabricvis much smoother to the feel than comparable woven gauze.

Fabric embodying a l0 X 5 carrier web and a fiberapplique weighingwithin the range of 1% to 6 grams per square yard is very porous sincethe threads in the carrier webare substantially spaced from each other,and because the fiber applique is so light and porous and permeable thatthere is but little resistance to the passage of fiuid through thefabric. Such material is well suited to sanitary napkin wrapper purposesbecause it readily permits menstrual fiuid to penetrate the wrapper forabsorption by the absorbent pad. Also, when the fiber applique is withinsaid weight range of 11/2 to 6 grams per square yard, there is suchrelative paucity of fibers per unit of web area that a large percentageof the fibers will directly contact adhesive bearing thread portions tobe thereby adhesively bonded to the carrier web. Hence, the applique, asan entirety, is effectively bonded to the carrier web so that detachmentof the fiber appliquerfrom the carrier web by rubbing and scufiing doesnot readily occur.

Fiber faced webs such as described, notwithstanding their stability dueto the adhesive interbonding of the threads in the thread carrier Web,are very soft and :pliable so vas to be readily conformable to absorbentpads A 9 to make sanitary napkins and such webs are readily foldableabout such pads by high speed, automatic pad wrapping mechanism. Thethread portions which are free of adhesive intermediate bondedintersections contribute substantially to the softness of the web asdoes also the working of the threads incident to the passage of the webthrough a calender as aforesaid, the latter operation probably servingto break up the continuity of the adhesive coatings along the threadportions intermediate some of the bonded intersections or perhaps toreduce the thickness of the adhesive coatings, to make them moreflexible. The low twist, fine denier, multiple filament, Very fiexiblethread construction, also contributes to this softness as aforesaid.

From the foregoing it will be seen that Whereas limitations in respectof the manufacture of gauze necessitate the use of constructions whichprovide much greater strength than is required in a sanitary napkinwrapper and also greater stiffness than is desired, the cross-laidthread `webconstruction herein described permits much greater freedom inthe selection of threads and permits the use of much lighter or thinnerthreads which nevertheless provide,` adequate tensile strength forsanitary wrapper purposes. The lighter or finer threads which may beused in cross-laid fabrics are of adequate strength, `due `in part tothe adhesive bonding of the` filaments to each other, and probably 'to agreater extent, to the fact that the threads are made of continuousfilaments.

, The low twist multiple filament threads employed for making thecarrier web will normally assume positions with their flat facesparalleling the plane of the web andsuch fiat faces of the relativelycrossing threads provide fairly wide fiat areas which are adhesivelybonded to` each other. Effective adhesive bonding is, therefor, easilyattained. Similarly, the fibers of the fiber applique are mosteffectively bonded to the carrier web because of the wide adhesivebearing faces which said threads present` to the fibers. i'

The 30 and 40 lament thread constructions described as having `beenemployed in practical products, are not critical or essential; .they maybe varied withinthe aforementioned fairly wide range and especially inthe direction oflower numbers of filaments in the threads. Lower denierfilaments and threads may also be used without making the web too weakfor sanitary napkin wrapper purposes.' Heavier weightsmay also be usedbut those specified are considered adequate and the use of threadweights which would equal woven gauze thread weights is unnecessary andundesirable for both functional and economic reasons.

An example of another satisfactory, lighter weight web would include a'fiber applique of 1.5 grams per square yard on a cross-laid thread webof 4 x 4 construction composedof low twist, multi-filament, lengthwiseand crosswise threads of 75 denier formed of 30 filaments.

Stable cross-laid thread fabric such as described, may be formed of lowtwist, cross-laid threads to suit various uses, the specifications ofthe threads within the stated ranges and the` closeness of their laybeing selected to suit the various uses. Such fabric may be providedwith a fiber applique of suitable weight or density if` desired or thefabric may be used without such applique as best suits the specificpurpose for which the fabric is selected.

Various combinations of the above mentioned Vvariable factors may be`employed to obtain suitable cross-laid fabrics for sanitary napkinwrapper and other purposes, and other changes may be made whileretaining the principles of and attaining the attributes of thedescribed constructions. i

I claim: i i

1. Non-woven netting comprising two sets of spaced threads disposed inface-to-face relation to each other with the threads of one setextending transversely of those ofthe other set and wholly on one sidethereof,isaid sets f threads being adhesively bonded to each other atthe crossingsof their threads, the threads of at least one of said setscomprising multiple lament low twist threads having a twist less than 6turns per inch and a denier within the range of 30 to 150, whereby arelatively light pressure on said low twist threads will flatten thethreads and increase their flexibility.

2. Non-Woven netting comprising two sets of spaced threads disposed inface-to-face relation to each otherA with the threads of one setextending transversely of4 those of the other set wholly on one sidethereof, said sets of threads being adhesively bonded to each other atthe crossings of their threads, the threads of at least one of said setsbeing of low twist, multiple filament construction in which thefilaments are of a denier within the range of about 1 to 15 and thetwist is less than 6 turns per inch.

3. Non-woven netting comprising two sets of spaced threads disposed inface-to-face relation to each other with the threads of one setextending transversely of those of the other set wholly on one sidethereof, said sets of threads being adhesively bonded to each other atthe crossings of their threads, the threads of at least one of said setsbeing of low twist, having a twist less than 6 turns per inch, and ofmultiple filament construction of a denier within the range of about 30to 150 and formed of filaments having a denier within the range of about1 to 15.

4. Non-woven netting comprising two sets of spaced threads disposed inface-to-face relation to each other with the threads of one setextending transversely of those of the other set wholly on one sidethereof, said sets of threads being adhesively bonded to each.v other atthe crossings of their threads, the threads of at least one of said setsbeing of low twist, having a twist less than 6 turns per inch, and ofmultiple filament construction with their portions which cross portionsof the threads of the other set flattened and widened to provide greaterflexibility as well as enlarged areas of engagement and adhesiveattachment to said threads of the other set.

5. Non-woven, fiber-faced netting comprising two sets of spaced threadsdisposed in faceto-face relation to each other with the threads of oneset extending transversely of those of the other set Wholly on one sidethereof, said sets of threads being adhesively bonded to each other atthe crossings of their threads, the threads of at least one of said setsbeing of low twist construction having a twist less than 6 turns perinch, with the portions of said low twist threads which cross portionsof the threads of the other set flattened and widened to provide greaterflexibility and enlarged areas of engagement and adhesive attachment tosaid threads of the other set, and a non-woven Vapplique of fibersattached to a face of said web. i i

6. Non-woven fiber-faced netting comprising two sets of spaced threadsdisposed in face-to-face relation to each other with the threads of oneset extending transversely of those of the other set wholly on one sidethereof, said sets of threads being adhesively bonded to each other atthe crossings of their threads, the threads of at least one of said setsbeing of low twist, having a twist less than 6 turns per inch, and ofmultiple filament construction with their portions which cross portionsof the threads of the other set iiattened and widened to provideenlarged areas of engagement and adhesive attachment to said threads ofthe other set, and a non-woven applique of fibers secured to a face ofsaid web, said web and applique being calendered whereby said appliqueis compacted in the areas of said threads but preserved in comparativelyfluffy condition in the areas of the interstices of said web.

7. Non-woven netting comprising at least two sets of spaced threads oflow twist construction disposed in facetofface relation to each otherwith the threads of at least one set extending transverselyV of those ofanother set, said threads having a twist less than 6 turns per inch, the

threads of said one set having adhesive applied discontinuously alongtheir lengths and the threads of said other set being -free of adhesiveexcept where they cross and engage adhesive-bearing areas of the threadsof said one set, the interengagement of lsaid threads in said adhesivebearing areas serving to adhesively bond said thread sets to each other.

8. Fiber-faced, non-woven sheet material having a web comprising atleast two sets of lspaced threads disposed in face-to-face relation toeach other with the threads of one set extending transversely of thoseof the other set wholly on one side thereof, the threads of at least oneof said sets of threads having adhesive along their lengths, saidadhesive bonding crossing thread portions to each other to thereby bondsaid sets of threads to each other, some of the thread portionsintermediate said bonded crossings being substantially free of adhesive,the threads of at least one of said sets being of low twist, multiplefilament construction having a twist less than 6 turns per inch andbeing of a denier within the range of about 30 to 150, and a non-wovenfacing of fibers on a face of said web engaging the adhesive on saidadhesive-bearing threads and thereby attached toV the web.

9. A sanitary napkin comprising an absorbent pad and a wrapper enclosingsaid pad, said wrapper comprising at least two sets of spaced threadsdisposed in face-to-face relation to each other with the threads of oneset extend ing transversely of those of the other set entirely on oneside thereof, at least one of said sets of threads comprising low twist,multiple filament threads having a twist less than 6 turns per inch andbeing of a denier within the range of 30 to 150, whereby said low twistthreads respond to forces on the wrapper to assume a flattenedcross-sectional form which falls generally into the plane of theadjoining surface of said absorbent pad to thereby provide a smoother,softer and more lieXible surface with the pad.

l0. A sanitary napkin having an absorbent pad and a wrapper enclosingsaid pad, said wrapper comprising a set of spaced threads which extendin one direction, and a second set of spaced threads which extendtransversely of the threads of said first mentioned set entirely on oneside thereof, said sets of threads being adhesively bonded to eachotherat the crossings of their threads, and the threads of both sets being oflow twist, multiple filament construction, said threads having a twistof less than 6 turns per inch, said wrapper being significantly moresupple than conventional woven cotton gauze of like mesh made of 30swarp and 40s filling threads, and a nonwoven applique of fibers on aface of said wrapper.

1l. A sanitary napkin having an absorbent pad and a wrapper enclosingsaid pad, said wrapper comprising a set of spaced threads which extendin one direction, and a second set of spaced threads which extendtransversely of the threads of said first mentioned set entirely on oneside thereof, said sets of threads being adhesively bonded to eachotherat the crossings of their threads, the threads of both said sets beingof low twist, having a twist less than 6 turns per inch, and saidthreads being of multiple filament construction having a denier vwithinthe range of 30 to 150, said wrapper being calendered and the filamentsthereof caused to fan out to form thin fiat crossing thread portionshaving a combined thickness which is significantly less than the sum ofthe normal thicknesses of said threads transversely of the plane of theWrapper.

l2. A sanitary napkin having a wrapper and an absorbent pad, saidwrapper comprising a set of spaced threads which extend in onedirection, and-a second set of spaced threads Iwhich etxend transverselyof the threads of said first mentioned set entirely on one side thereof,the threads of at least one of said sets being of low twist, multiplefilament construction having a twist less than 6 turns per inch andhaving a denier within the range of about 30 to 150, the filamentshaving a denier 12 within the range of 1 to 15, and said sets of threadsbeing adhesively bonded to each other at the crossings of their threads.

13. A sanitary napkin having an absorbent pad and a Wrapper enclosingsaid pad, said Wrapper comprising a thread web having a set of spacedthreads which extend in one direction, and a second set of spacedthreads which extend transversely of the threads of said first mentionedset entirely on one side thereof, the threads of both of said sets beingof low twist, multiple, fine filament construction, the low twist ofsaid threads being less lthan 6 turns per inch so that 1where saidthreads cross one another, the filaments fan out to form wide but thin,fiat crossing thread portions which have their fiat faces in engagementwith each other, said fiat faces being adhesively bonded to each otherto thereby stabilize the thread positions in the fabric, and a non-wovenapplique of fibers on a face of said thread web and adhesively securedto some of said threads.

14. A sanitary napkin having an absorbent pad and a wrapper enclosingsaid pad, said wrapper comprising a thread web having a set of spacedthreads which extend in one direction, and a second set of spacedthreads which extend transversely of the threads of said first mentionedset entirely on one side thereof, the threads of at least one of saidsets having a twist of less than 6 turns per inch, one of said sets ofthreads having adhesive applied thereto along their lengths and thethreads of the other set being free of adhesive but engaging saidadhesive on said adhesive-bearing threads and being thereby bonded tosaid adhesive-bearing threads, and a non-woven applique of fibers on theside of said wrapper formed by said adhesive-free threads, some of thefibers in said applique engaging said adhesive bearing threadsintermediate said transversely extending threads to thereby adhesivelyanchor said applique to said thread web, said .applique being pressedinto said thread web and being compacted therewith at crossings of thefibers over the threads but remaining comparatively fluffy in the areasof the interstices of the web.

15. Non-woven netting comprising two sets of spaced threads disposed inface-to-face relation to each other with the threads of one setextending transversely of and crossing those of the other set wholly onone side thereof, said sets of threads being adhesively bonded to eachother at at least some of the crossings of their threads, at least oneof said sets of threads comprising highly fiexible, low twist threads,having a twist less than 6 turns per inch, the netting being calenderedand said low twist threads being thereby caused to fan out to form thin,flat, widened portions at their crossings, whereby the prominence ofsaid crossings is reduced, the area of adhesive attachment of the threadportions in said crossings is increased, and the fiexibility of thenetting is increased.

16. Non-woven netting comprising two sets of spaced threads disposed inface-to-face relation to each other with the threads of one setextending transversely of and crossing those of the other set wholly onone side thereof, said sets of threads being adhesively bonded to eachother at at least some of the crossings of their threads, both of saidsets of threads consisting of highly flexibly, low twist threads, havinga twist less than 6 turns per inch, the netting being calendered andsaid low twist threads being thereby caused to fan out to form thin,flat, widened portions at their crossings, whereby the prominence ofsaid crossings is reduced, the area of adhesive attachment of the threadportions in said crossings is increased, and the flexibility of thenetting is increased.

17. Non-woven sheet material having a web comprising at least two setsof spaced threads disposed in facetofface relation to each other withthe threads of one set extending transversely of those of the other setwholly on one side thereof, the threads of at least one of said setsbeing of low twist, multiple filament construction having a twist lessthan 6 turns per inch and being of a denier within the range fo about 30to 150, one of said sets of threads having adhesive along their lengthsand the other set of threads being free of adhesive but being bonded tosaid adhesive-bearing threads by the adhesive carried by the latter.

18. Fiber-faced, non-Woven sheet material having a web comprising atleast two sets of spaced threads disposed in face-to-face relation toeach other With the threads of one set extending transversely of thoseof the other set and wholly on one side thereof, at least one of saidsets of threads being of low twist, multiple lament 14 construction witha twist less than 6 turns per inch, and a non-Woven facing of fibers ona face of said web including a quantity of thermoplastic fibers whichare activated by hot calendering of the web to provide bonding 5 of thethreads and ber facing in relatively iixed positions.

References Cited in the le of this patent UNITED STATES PATENTS 102,564,689 Harwood et al Aug. 21, 1951 2,696,243 Holland Dec. 7, 19542,771,118 Bobkowicz Nov. 20, 1956

